[Qemu-devel] Re: [PATCH 00/12] AHCI emulation support v4

[Alexander Graf]

On 02.12.2010, at 11:43, Gerd Hoffmann wrote:

> On 12/02/10 00:29, Alexander Graf wrote:
>> 
>> On 24.11.2010, at 12:44, Gerd Hoffmann wrote:
>> 
>>> On 11/23/10 15:34, Alexander Graf wrote:
>>>> This patch adds support for AHCI emulation. I have tested and verified it 
>>>> works
>>>> in Linux, OpenBSD, Windows Vista and Windows 7.
>>> 
>>> Also seabios ;)
>>> http://cgit.freedesktop.org/~kraxel/seabios/log/?h=ahci
>> 
>> I broke that one with v7 of the ahci patchset apparently. Sorry about that 
>> :). Since Linux and Windows still happily boot, it's probably something 
>> missing on your side :(.
> 
> No.  DMA is broken (probably non-ncq only).
> 
> Commit c29947bbb0978d312074ec73be968bfab1b6c977 broke your way of kicking dma.
> 
> /me papered over it with the attached patch.  The RightWay[tm] to fix it is 
> probably to put a "bmdma_cmd_writeb(bm, 0, 0)" to the approximate place.  Or 
> refactor ide dma in a way that you don't need to kick it in such a hackish 
> way in the first place.

Ugh. Thanks for digging through that. I agree, the way DMA is handled atm is 
very bogus and not pretty at all. Maybe we should try to refactor it so dbdma 
can be used as well? Not sure how all of that works yet though.


Alex